Electric flow meter



July 23, 1940. E. F. sTovER 2,208,609

' ELECTRIC- FLOW METER Filed May 22, 193'! '5 Sheets-Sheet 1 52 Fig.1.

, riventar Emoryi'rankfltouer Jllly 1940- I E. F. aTOVER 2,208,609

ELECTRIC FLOW METER Y Filed May 22, 1957 Y SSheets-Sheet 2 I A I 57 3 Ira/enter:

l'rrwryfranhfzover Jul) 23, 1940. E. F. STOVER ELECTRIC FLOW METER Filed ma 22, 19s:

3 Sheets-Sheet 3 .5 Iimtimrzak Zero 137 Zero 1 I? 44 F J ,J'ecaIaIZZ/ZIw/Z I I in circuit Inventor" .Z'mryFmn/cJtover m T i 3 Patented July 23, 1940 PATENT OFFICE q ELECTRIC FLOW METER Emory Frank Stover, Vvynncwood, Pa. Application May 22, 1937, Serial No. 144,156

21 Claims.

My invention relates to a measuring. system and apparatus for measuring and indicating physical and other quantities to be measured, and particularly to meters for measuring the flow of fluid in conduits. a

The object of my invention is to provide a system for controlling the current in an electrical circuit, whereby the current in a branch of the f circuit will be caused to vary directly as the resistance included in said branch. v

A further object is to provide a system of obtaining a square law by varying the resistance in a firstbranch circuit until it is proportional to the square root of the resistance included in a second branch circuit.

A further object is to provide novel apparatus which is actuated by a condition, or quantity, which varies directly as the quantity to be measured, and control the resistors included in branching electrical circuits for obtaining the square, root of said quantity to be measured.

A further, object is to provide a meter for measuring the flow of fluid through a conduit,

' including a primary differential producingdevice, giving a square 'root relation between the rate of flow through the conduit and the differential pressure, and employ in the meter the use of the principle of the flow of currents in branching electrical circuits for extracting the square root of said diiferential pressure.

These together with various'other novel features ofconstruction and arrangement of the parts, which will be more fully hereinafter de-- scribed and claimed, constitute my invention. 5 Referring to the accompanying drawings:

Fig. 1 is a perspective view of my novel meter,

showing the electrical circuits diagrammatically.- Fig. 2 is a central vertical sectional view of the I meter shown in Fig. 1. Fig. 3 is a vertical section on line 33 Fig. 2.

. Fig. 4 is .a partial plan view'of Fig. 3.

' .Figs. 5 and s are diagrams illustrating the velectrical circuitsthroughout the various steps of my novel system. v

Fig. 'l is a diagram illustrating the electrical vcircuits including aVenturi tube and ,a manometero In the drawings in which like reference charthereby controlling the current flowing in theelectrical circuits. a

55 The meter shown in Figs. 1 4, will be first provided. The members [5 and described so that the system of controlling the circuits can be better understood.

A primary metering device, in the form of a Venturi tube I0, is connected in a conduit i2, through which fluid flowing in the direction of 5 the arrow is to be measured. A manometer II, in the form of a U-tube, having a high pressure member i5 and a low pressure member i6, is l6 contain mercury l8. Reservoirs 20 and 2i are mounted 10 upon the open ends of the members l5 and I6, andare'connected by pipes 22 and 23 with the high and low pressure sides of the Venturi tube Ill, for subjecting the mercury to the differential pressure produced by the Venturi tube, which 1 pressure is proportional to the square of the rate of flow through the conduit i2.

The reservoir 20 has a plug 24, of insulation material, through which passes a conductor of an electric circuit, .such as shown in Figs. 1 and 7. 20

A main circuit 25 includes a resistor R and conductors 28 and 2'| In Figs. 5 to 7 a battery 28 is shown as a source of direct current,

The main circuit may be adapted for alternating current by employing a transformer 30, as

extends through the plug 24 and into the mercury 35 in the U-tube, and makes contact with the mercury.

.A resistor R" is located in the member l5 0! the U-tube and extends a maximum length intothe mercury. The resistor R" is connected with I a conductor 39, included in the shunt circuit. Said conductor 39 extends through the plug 24, and is connected with a moving coil of 'a galvanometer 34, and also to the secondary S2, having a junction ill with the main circuit 25.

The secondary S2 is included in the shunt circult to provide sufiicient voltage to overcome the resistance of the conductors, and various parts included in the. shunt'and main circuits,

except the resistance of the resistor R and the resistor R" between the zero and the level of the mercury.

In Figs. 6 and 'Z a battery 31 is shown included in the shunt circuit for overcoming the resistance of the conductors, and takes the place of the u secondary coil 8:, shown in Fig. 1. The shunt circuit, shown in Figs. 6 and 7, has a junction 4| with the main circuit 2!.

Fig. 1 shows an adjustable resistor R5 included in the main circuit adapted for changing the range of the meter to accommodate different maximum values of differential pressure, but keeping the same travel of a pointer which is movable with the contact A. The adjustable resistor R5 is connected in series'with the resistor R and is adapted for accommodating diiferent maximum values of the second resistor R", requiring a change in the resistance of the resistor R for keeping it at the same value.

The shunt circuit 38 includes an adjustable resistor Re adapted for adjusting the meter to different resistances of conductors between the manometer and the meter. The resistor R is a fixed resistance with negative temperature coefficient adapted for correcting line resistance for temperature changes.

"A calibrated resistor Rs is adapted to be utilized as a means of checking the setting of the meter by being substituted in the shunt circuit for the resistance. which the resistor R" would have if certain differential pressureswere applied to the manometer. A switch 42 is provided for including the resistor Rs in the shunt circuit.

An adjustable resistor R0 is included in the standard circuit for adjusting the resistance of the conductors of the standard circuit, hereinafter described. a

, The contact-plate ti, .forming the contact A, is in sliding contact with the resistorlt' and is The surface level of the mercury in the tube It forms a movable contact B upon the resistorR" and closes the shunt circuit between the resistor.

R" and the portion of the conductor 36 extending into the mercury in the tube It.

The contacts A and B are shown in Figs. 5 and I 6 in the form of sliding contact devices 43 and 44 adapted to be operated manually in contact with the resistors R. and R", for carrying out the system of controlling the circuits, as more fully hereinafter described.

Referring to Figs. 1 to 4, when there is no flow through the conduit II the mercury will stand at the zero level in the tube II. When there is any flow through the conduit I! the differential pressure depresses the mercury to a level, or point of contact B, at which point the shunt circuit 38 is closed where the resistor R" enters the mercury. The portion Rs, of the resistor R" lying between the zero and the mercury contact B, will be directly proportional to the differential pressure' adapted for varying the resistance, an will .be later described.

Y The shaft 40 is rotatably mounted upon the frontand back plates 41 and 44. loosely mounted upon the shaft 4| is a sleeve It, having ,secured thereon a hub I l and a worm wheel II,

which latter meshes with a It, secured base plate II anda top plate 58. The shaft 54 is continuously rotated by a synchronous motor 51, through reduction gears 58 and 59. Said sleeve 50 also has secured thereon a gear 60, which meshes with a larger gear 5|, secured on a counter shaft 62, having secured thereon a smaller gear 63 which meshes with a gear 64 secured on the shaft 46 and continuously rotates the latter at a slower speed;

- A paper chart 65 is positioned for rotation in front of the front-plate 41 and is secured to the shaft 46 by a thumb nut 68 and a washer ill in the usual manner.

The disk 45 is held against rotation on the shaft 46 by a bracket Ill, secured upon the disk, and a bar ll, secured in the front and back plates 41 and 48. An adjusting screw 12 is threaded through the bar I I. The bracket 10 is positioned betwen the head of the screw and a spring 13, which latter is interposed between the bracket and the bar ll. By turning the screw 12 the angular position of the disk may be adjusted.

The disk 45 has two circular contact strips 15 and 16 secured upon its rear face, as shown in Figs. 2 and 3. A swinging contact'plate I1 is adapted for closing a circuit by making contact with said strips. Said strips I5 and 16 are ar-.

ranged in parallel relation to each other and extend through arcs corresponding to the length of the resistor R. v

The swinging plate I1 is mounted upon a radial rod II, which is secured in said hub 5i, secured upon the sleeve ill. Thehub Si is formed of insulation material. The rod I8 is provided with a head 19. The swinging plate 11 has a tubular portion 80 which is rotatably and slidably mounted upon the rod It. A coiled spring 8! is mounted upon the rod II and has one end thereof secured upon a pin 82 on the hub 5i and its opposite end in engagement with a pin 03 secured on the portion 80 of the contact plate 'I'I. spring ll tends to slide the contact plate ll'outthe free end of the contact plate against said strips II and I6 on the disk, for opening and closing a circuit including conductors 85, I6 and 81, and including the secondary coil 84 as a source of potential.

The contact A, or plate Ii, which is in slidingpointer 95 adapted to be moved relatively to a dial; having a graduated scale 98, upon said front p a e. l

The arm 14 is secured upon a sleeve 91, freely I rotatable upon the shaft 48. Secured to said sleeve 91 is a pulley it over which passes a cable 9!, driven by a drum lfll' secured upon a shaft I" mounted for rotation upon the front and 'back plates 41 and. The shaft III is rotated in either direction by a standard type reversing shaded p ole motor In through gears I04 and III.

The cable 19 embraces a pulley It! secured on a shaft III, which shaft is mounted for rotation upon the plates 41 andllh The shaft ill extends through the front plate 41v and has secured thereon a pen arm Ill, carrying a pen I",

adapted formarking upon the chart 4'.

The arm '8 of the frame II is positioned upon wardly against the head 19 and also tends to hold upon a shaft .4, rotatably mounted in a the shaft 4' between the disk 4! and the hub 15 11 will pass over said arm 93 as the plate 11v is continuously rotated in the direction of the arrow, Fig. 1.

After the plate 11 has passed over and beyond the arm 93 it is urged by the spring 9I against the strips and 18, for completing the circuit including the conductors 85 and 89. When the plate 11 passes beyond the ends of the strips 19 and 19 it opens said circuit, and said plate is pressed against the face of the disk 95 by the torsion action of the spring 9I.

An eccentric track, or rail, H9 is secured upon the rear face of the disk 95, and the outer edge of the swinging plate 11 rides upon the inner surface of the rail H9, and the eccentric inner surface of the rail causes the plate 11 to slide upon the radial rod 18, toward the axis of the disk, and against the compression action of the spring 8i. The eccentric rail II 9 directs the contact plate 11. in its rotation over the disk, so that'when the plate 11 leaves the end of 'the rail I I9 it will be held against outward movement upon the rod 18 by the inner cylindrical surface of the strip 15, and the spring 8I will still be compressed. The contact plate 11 will thus be held out of contact with the outer strip 18, until the trailing edge of the plate 11 passes-over the arm 83, and said plate is rotated by said a m 93 about the radial rod 18, against the torsion action of the spring 8|.

When the contact plate 11 is thus released from said inner cylindrical surface of the strip- 15, the spring 9i pushes said plate 11 outwardly upon the rod 18 until it takes against the head The further rotation of the rod I9, about the axis of the shaft 99, causes said plate 11 to pass off the arm 93, and said plate 11 then drops upon and makes contact with the two strips 15 and 19, thus completing thecircuit including the conductors 85 and 89.

When the pointer 95 is at the zero point of the scale 99 the arm 93 will be in the position indicated by the dotted line marked zero in Fig. 3, so that the swinging contact plate 11 will not engage the two strips 15 and-19, during any part of the revolution of said plate 11, about the axis of the shaft 99. When the arin 93 is at the zero position the contact plate 11 will not be released from the strip 15, by the arm 93, until the plate 11 has passed beyond the ends of the strips 15 and 19.

When there is fluid passing through the conduit I2 the arm 93 will be rotated, as hereinafter more fully explained, to a osition at the left hand side of the zero line shown in Fig. 3, and thus the arm 93 will. release the plate 11 and allowit to engage the strips 15 and 18 and complete the circuit between said strips for a period of time during a fraction of the revolution of the contact plate 11, corresponding to the quantity of fluid passing through the conduit I2.

An integrating device, or totalizing device, II2

I is provided for showin the total flownf fluid through the conduit I2. The device H2 includes any well known form of magnetic clutch operated indicator. Amagnetic clutch I.I3 is rotated continuously by a shaft II9, driven by a worm wheel II5, secured on the shaft H9 and meshing with a worm II8. h

The worm H9 is secured upon the vertical shaft 59, which is continuously rotated bythe motor 51. --The clutch II3, as shown in-Fig. 2, comprises arms II1, secured on the shaft II9.

Upon the arms II1 arefriction pads III which.

are-adapted to engage and rotate a disk I29, secured to a shaft III of the integrating, or counting device I I 2. The disk I29 is moved into frictional engagement with the pads II9 by the coils I22 and I23, which coils magnetize the casing m when the circuit including the conductors 99, 99 and 91, is closed by the swinging contact plate 11 closing the circuitbetweenthestrips 19 and 19.

An integrating. or counting device I29, similar to the device H2, isprovided at a distant location from the meter, and is adapted to be operated by extension conductors I28 and I21 controlling the circuit for operating the device II2.

A separate motor I29 is provided for operating the clutch I29, of the integrating device- I25. The motors 51 and I29 are shown connected by conductors I39 and I3I which are connected with the line wires 32 and 33, for continuously rotating the motors 51 and I28.

An adjustable member in the form of an arm I 39, of insulation material-is mounted for rotation upon the horizontal shaft 98. The arm I39 may be set in different radial positions by hand and it is held against accidental rotation by a spring I35, shown-in Fig. 2. Said spring is in frictional engagement with the rear surface of the front plate 91. semicircular metal contact plates I39 and I31 are secured upon sald'member; or .arm I39. A spring contact plate. I38 is carried by the arm 99 of the frame 9|.

-Said contact plate I38 is adapted to makecontact with the plate I36 for completing a circuit including the conductors 85, I99 and I9I',

or for making contact with the plate I31 for completing a circuit including conductors 85, I99

and I92 for operating a reversing relay I93, which in turn is connected by suitable conductors I99,

and adapted for controling a reversing motor.

I99, having a pinion I99 meshing with a gear wheel I91. Said gear {wheel I91'is rotatably mounted upon a bearing I98 upon the housing of a valve I59 adapted for regulating the flow of fluid through the conduit I2. The valve stem I9I is provided with a threaded portion which the hub of the gear wheel I91 and is adapted for opening tnd closing the valve I59 by the reversing motor I99.

The auxiliary pointer arm which flow is to be measured by the meter. Should the flow vary from the desired quantity indicated by the set position of the control pointer arm I39, the pointer arm 99 will move and cause the contact plate I38 to engage either the contact plate I39 or the contact plate I31, and

thus/control the circuits through the reversing relay I93, for opening or closing the valve I59,

until the flow through the conduit I2 is restored I39 provides meansv for controlling the flow through the conduit I2,

' is in engagementwith the threaded aperture of through the conductors I51, I58 andII58, which are connected with the line wires 32 and 33. The

movable coil I99 is secured upon a shaft carry-- nected in the shunt circuit as, by the conductors '39, and having the secondary S: as a source'of potential. The other winding upon the movable coil I" is energized, through conductors I62 and 163, by the standard circuit I64 including the secondary S3.

The secondary S: supplies a current of standard value for moving the coil ISO in the opposite direction from the. action of the current of the shunt circuit 38. The shunt circuit 18 has a junction 40 between the secondary S: of the shunt circuit and the secondary S1 of the main circuit. It will be understood that the secondary Szis included in the shunt circuit 38 for over! coming the resistance of the contacts, conductors and of the galvanometer 34, but not the resistance of the resistors R and .R

The adjustable resistor R9 which is included in the standard circuit I64, provides means for varying the current of the standard circuit to any desired standard.

The galvanometer 34, connected in the above manner, provides a means for comparing the deflection produced by the current through the shunt circuit with the deflection produced by a standard current, the latter current having a value which is a fixed proportion of the potential of the main circuit 25 divided by the resistance of the entire resistors A R and R5. Current through the shunt circuit is subjected to the resistance of the portion of the resistor R" between the zero point and the level of the mercury,

which is proportional in resistance to the diiTerential pressure, or tea quantity to be measured.

The current of the shunt circuit is further regulated by changing the position of the contact A'upon the first resistor R until suflicient current is carried off from the main, circuit through the contact A and through the shunt to .balance the galvanometer between the shunt and standard circuits. When the galvanometer is so balanced the length of the portion of the resistor R, between the zero end thereof and the contact A, will form a first branch circuit which is proportional in resistance to the square root of the resistance of the second branch, or shunt, circuit, controlled by the portion of the vresistor R" between the zero ,end thereof and the contact B, or level of the mercury.

The position of the contact A, relatively to the length of the resistor R, will indicate a value directly proportional to the flow through the conduit I2, and the pointer 95, which moves with the'contact A, will indicate a reading upon the dial 96 which is directly proportional to the flow through the conduit.v

The galvanometer 34 controls circuits for operating the reversing motor I03, which latter in turn moves the contact] A relatively to the length of the resistor R. through .the medium of the cable I! and the arm' 04. The motor I" is supplied with current through conductors I" and 161, connected with the wires IIII and lil, whichare connected with the line wires 32 and '3; I

The direction of rotation of the motor I is controlled by the arm IOI which is actuated by the movable. coil of the galvanometer 34. The arm III when moved in one direction completes a circuit through conductors I and I for actuating control means, not shown in the drawings, oi the motor Ill, fdF-causingit to rotatein one direction, and when thearm- III is moved in the opposite direction it will a circuit either alternating or direct current. Figs. 5, 6

and 7 illustrate circuits including a battery 28, as a source of direct current.

A spring controlled galvanometer I65, is shown in Figs. 6 and '1, having a set reading equal in value to the potential E of the main circuit divided ,by the entire resistance of the resistor R, with the contact A removed.

Scales I16 and I11, graduated from zero to 100%, proportionally to the resistance of the resistors R and R", are positioned adjacent to pointers I18 and I19 mounted upon the sliding plates 43 and 44, which form the contacts A and B, respectively.

The galvanometer I65 is adapted for indicating when the contact A is adjusted to a position upon the resistor R in which the current I3, through the shunt, equals the set reading of the galvanometer.

In carrying out my system the contact B is moved upon the resistor R", as indicated in Fig. 6, to include a portion R3 of the resistor R" having aresistance directly proportional to a quantity to be measured. The contact A is then adjusted upon the resistor R to a position to carry a sufficient current through the resistance of the portion R3 of the resistor R to cause the galvanometer to return to and indicate said set reading, whereby the resistance of the portion R1 of the first branch is proportional to the square root of the resistance'of the portion R: of said second resistor R" included in the second branch, and the length of the portion 111 of the scale I16 will be equal to the square root of the length of the portion 1/: of the scale I11, thus providing a system of obtaining the square root of the quantity to be measured, as indicated by the position of the contact A, and its pointer, relatively to the length of the scale I16.

My novel system of obtaining a square law by causing a current flowing in a branch of an electric circuit to vary directly as the resistance in that branch, is illustrated in the diagrams Figs. 5, 6 and 7. in which the contact A is shown in the form a, sliding contact plate l3, manually movable throughout the length oi the resistor R'.. This plate 18 corresponds to the mechanically movable contact 35, shown in Fig. 1. The

contact B, as shown in Figs. and 6, is in the form 01' a sliding contact plate 44, manually movable throughout the length of the resistor B". This plate 44 corresponds to the mercury contact B, shown in Fig. 1.

The resistors R and R" have uniform resistance throughout their lengths. Assuming that E and Is are constant, that all the conductors are of heavy wire and of negligible resistance relatively to the resistors R and R'T, and

that the resistance of Rf equals the resistance of r R' when the contacts A and B are in thepositions shown in Fig. 5, the current I1 through the flrstbranch equals the current I: through the second branch, since R equals R", and E quals Es.

Referring to Fig. 6;

. By Kirchofl's law for flow of current inbranching circuits:

I2 equals 11 plus Ia. From Ohms law: I

equals I1 equals 1, equal.

If contacts A'and B are moved irom the 9001- tions shown in Fig. 5 to the posltlonsshown in Fig. 6. the part R1 of R above A is now carrying the current Ia and also the current I1, hence the voltage drop Ra (I1 plus 11) from 100% to A is greater than before, and since the total drop E from 100 to zero is still the same, the drop in the branch from A to zero, which equals E minus (100 to A) will be diminished. Since for the branch A to zero I1 equals 11 will bediminished also.

If' this current I1 can be shown to diminish in direct proportion to R1 then from Ohm's law,

M, I times the square root of Rs. An increase in the resistance R: will require a increase in the voltage applied to R: to maintain the constant current Is. This increased-voltage than R1 increases.

is obtained by moving the contact A toward the high potential end of R. But due to the decreased voltage drop in the portion A to 100%. caused by the constant current I3, more of the original voltage E is left to drive the current 11 through the resistance R1. As a result the voltage drop across R1 increases. more rapidly It actually increases as the product of R1 and 11.

If the resistor R has uniform resistance per unit length. this increase in 11 is directly proportional to the increase in R1. Therefore the change in the voltage drop across R1 is proportional to the product of R1 and I1 or its equivalent MR1.

Since the result of multiplying any quantity by itself is a squared term, we have a voltage drop across R1 proportional to the square of R1 and since this voltage drop across R1 is the voltage necessary to send a constant current I: through R1. this voltage will be directly propor-' tional to Rs. But since this voltage is directly proportional to R1 we -have R1 equal to 11133, or R1 equal to the square root of LRs, where L is a constant.

That current 11 varies in direct ratio to R1 can be shown mathematically as follows: The total voltage E is used up according to the following equation:

E- equals R211 plusRaI: plus R111. Since I: is

constant E equals 11 (R: plus R1) plus NR2, where N is a constant.

E equals 11R plus NR 1; equals Since E is constant:

I equals N,N plus where N: equals the ratio of constant N1 over constant R. 11 equals N3 plus N4R1.

Thus 11. is shown to be equal to a constant plus a constant times R1 or 11 varies directly with R1.

From Kirchoifs law, above stated, for flow of current in branching circuits:

I1 equals I1 plus 1:. (Equation 1) From Qhms law:

'1, equals g rl; equals %-I equals %-equals R From Equations 1 and 2;

2 a a s =2- R equals R plus RI equals R1 plus I, R plus I, Since E1 equals Ea.

E equals E1 plus E1, or E: equals E'-E1 R equals Ra plus R1, or R1 equals R'R1 Therefore,

E E I equals plus I 1 equals 5% plus I,

' (Equation 3) E'Ri-IiRtRi equals laRiR' plus IaR3R'- 3R1-I:R:Rr (Equation 4) Since the second and last terms are equal and of the same sign they cancel.

Dividing through by Is.

By assumins T. equals 12 R (Equation 5) the last two termscancel, leaving; R1 equals' RR. 7

. R, equals JRJZ' (Equation 6) 7 From Equation 5; R equals R1 Qquals (Equation .7) 1

If voltage E is kept constant, and current I: is kept constant by a change in the position of contact A for every change in the position of contact B, then the relation between R1 and R: is: 1 a

q R equals K /17; where K is a constant.

If R1 and R1 have uniform resistance per unit length then (Equation 8) 11 equalsK /i;

(Equation 2) Italy remains then to make u: on the scale R 1'77, Fig. 6, proportional to the resistance of the resistorB", and 111 proportional to the displacement of the pointer on the scale I", which indicates the square root ofthe resistance of the resistor R", to obtain a square law.

The above described system of obtaining a clutches III and I2! which control the totalizing devices H2 and I25, in the following manner: The motor 51 imparts a continuous rotary motion to the hub 5|, carrying the radial rod 10, and also rotates the chart 65 through the reduction gears 60, BI, .52 and-64, which rotate the shaft 45 on which the chart is secured.

The continuously rotatingradial rod carries the'swinging plate 11 around the rear face of the disk 45, in the direction of the arrows Figs. 1 and 3. The plate 11 as it passes from the ends of the contact strips I5 and I6 is held by the head 19 ofthe rod I8 at the proper distance from the axis of the hub 5| for causing the trailing edge of the plate ll to engage the rear face of the disk within the space between the hub and the end. of the eccentric rail 0' having the greatest radius. As the rod 10 continues to movethe plate 11 the outer edge of the latter will takcagainst the inner surface of the rail IIO, which flatter slides the plate 11 upon the rod 10 toward .the hub",

against the compression action of the spring lI.

' As the rod I0 continues to rotate the plate ll within therail IIO the latter will direct the plate 'Il into engagement with the inner cylindrical surface of the strip I5 as the plate Il passes'from the end of. the rail IIO to the strip I5, thus the plate 11 is still held out of contact with the other strip 15. when the rod 18 passes the arm 00 the swinging plate 11 will ride over the arm 03 and 'thus release the plate 11 from locking engagement with the strip I5. The spring II slides the plate ll upon the rod 10 and against the head".

When the rod 10 drags the trailing edge oi the plate 11 from the arm 03, the plate "will make contact with the two strips 15 and I6 and complete the circuit through the conductors 05 and 86 and energize the clutches I II and I20, which in turn operate the counters I I2 and I25. The strips 15 and I6 terminate'at the proper places upon the disk '45 so that the trailing edge of the plate 'l'l will leave'the ends of the strips when the pointer 95 is at the zero end of the rate scale 05, thus the counters H2 and I25 are operating at a constant speed for a period of time proportional to the position of the pointer 95, and arm 03, relatively to the rate scale 96. 4

The total discharge through the conduit I2 equals the rate of fiow multiplied by time, therefore the total time the counters H2 and I25 are operating will register the total discharge.

The rate of flow through the conduit I2 may be maintained at a set rate by the valve I50. The arm I34, forming the auxiliary pointer, is adjusted by hand, relativelyto the scale 86, for maintaining the desired flow. I If the rate of flow falls below the desired set rate the arms 03 and 94 move anticlockwise, as indicated by the arrows Figsjl and 3, and the spring contact plate Ill, upon the arm 94, will make contact with the semicircular plate I36, which is secured to the arm I34. A circuit including conductors 45, I40 and Ill will be closed by the engagement of the plates I36 and I38 and the motor I45 will be operated-by means of the reversing relay I4 3 in a direction for. opening the valve I50.- If the rate of fiow increases beyond the set rate the arms 03 and 04 will be moved in a clockwise direction, or

opposite to the arrow, and thespring contact plate I38 will make contact with the semi-circular contact plate I31 and complete.a circuit through conductors 05, I40 and I42 and operate the conduit I2 may be maintained at any def sired percentage of the maximum rate of flow, by manually adjusting the pointer, or arm I84, to any desired -position relatively-to the rate scale 95. e

I claim: V

l. A measuring system comprising a main electrical circuit including a source of potential, a first resistor in said circuit, a contact movable upon the first resistor, a shuntcircuit including said contact, a secondresistor included in said a shunt, means for varying the resistance of the second resistor included in said shunt.

2. A measuring system comprising a main electrical circuit including a source of potential, a first resistor in said circuit, a contact movable upon the first resistor, a shunt circuit including said contact, a second resistor included in said shunt, means for varying the resistance of the second resistor to a value directly proportional to a quantity to be measured, and a galvanometer included in said shunt adapted to indicate when the contact on the first resistor is adjusted to a position for carrying ofi a current through said shunt equal to the current flowing in the main circuit before said contact was applied to the first resistor, and the position of the contact relatively to the length of the first resistor is proportional to the square root of the value of the resistance of the second resistor included'in said shunt.

3. A measuring system comprising a main electrical circuit including a source of potential, a first resistor in said circuit, a contact movable upon the first resistor, a shunt circuit including.

said contact, a second resistor included in said shunt, said contact adapted to form a first branch between the zero end of the first resistor and said contact, means adapted for varying the length of the second resistor to form a second branch having a resistance value directly proportional to a quantity to be measured, a

galvanometer included in said shunt adapted for indicating when the contact on the first resistor is adjusted to a position for carrying off a current through said second branch equal to the current flowing in the main circuit, before said contact was applied to the first resistor, and the position of said contact from the zero end of the first resistor indicates aresistance value of said first branch which .is proportional to the square root of the resistance value of said second branch,

- and a source of potential included in said shunt adapted for overcoming the resistance of the galvanometer, conductors and contacts, exclusive-0t said first and second resistors.

4. A measuring system comprising a main elec- 5 trical circuit including a source of potential, a first-resistor in said circuit,-a contact movable upon said resistor, a shunt circuit including said contact, a second resistor in said shunt, said contact adapted to form a first branch between the zero-end of the first resistor and said contact, means adapted for varying the length of the second resistor to form a second branch having a resistance value directly proportional to a quan tity to be measured, a galvanometer included in saidshunt and having a set reading corresponding to a value equal to said potential divided by the resistance of the first resistor said contact adapted to be adjusted to a position upon the first resistor for varying the current in said shunt to the set reading of the galvanometer and the position of said contact from the zero end of the'first resistor indicates a resistance value of said first branch which is proportional to the square root of the resistance value of said second branch, and a source or potentialincluded in said shunt adapted'for overcoming the resistance of the galvanometer, conductors and contacts, exclusive of said first and second resistors.

5. A measuring system comprising a main electrical circuit including a source or potential, a first resistor. in said circuit, a contact movable upon said resistor, a shunt circuit including said contact, a second resistor in said shunt, said .contact adapted to form'a first branch between the zero end of the first resistor and said contact, means adapted for varying the length of the second'resistor to form a second branch having a resistance value directly proportional to a quantity to be measured, a galvanometer included in i said shunt, a standard circuit carrying a current which is a fixed proportion oi the potential of the main circuit divided by the first resistor and arranged for opposingthe deflection of the galvanometer caused by the current in the shunt circuit, said contact adapted to be positioned upon the first resistor for balancing the galvanometer between the standard and shunt-circuits and the position of said contact irom the zero end of the first resistor indicates a resistance .value of said first branch which is proportional to the square root of the resistance value of said second branch,

and a source of potential included in saidshunt adapted for overcoming the resistance of the .galvanometer, conductors and contacts, exclusive of said first and second resistors.

6. A measuring system comprising a main elec-.

trical circuit including a source of potential, at first resistor in said circuit, a contact movable upon the first resistor, a shunt circuit including said contact, a second resistor included in said shunt, said contact adapted to form a first branch between the zero end of the .firstresistor and said contact, means for varying the length or the second resistor to form a second branch having a resistance value directly proportional to a quantity to be measured, a galvanometer included in said shunt adapted for indicating when the contact on the first resistor is adjusted to a position for carrying off a current through said second branch equal to the current flowing ln'the main circuit before said contact was applied tothe first resistor, and a scale graduated proportionally to the length or the first resistor and located adjacent to the latter upon which scale the position of said contact indicates a resistance value or said first branch which is proportional to the square root of the resistance included in said second branch.

'7. A measuring system comprising a main 'electrical circuit includinga source oi potential, a first resistor in said circuit, a contact movable upon the first resistor, a shunt circuit including said contact, a second resistor included in said shunt, means for varying the resistance of the second resistor to a value directly proportional to a quantity to be measured, means controlled by the current flowing through said shunt and the second named means and adapted for ad- 5 justing the contact upon the first resistor to a position for maintaining said current through said shunt, whereby, the position of the contact relatively to the length of the first resistor is proportional to the square root or the value of the resistance of the second resistor included in said shunt.

8. A measuring system comprising a main electrical circuit including a source of potential, a first resistor insaid circuit, a contact movable upon the first resistor, a shunt circuit including said contact, a second resistor included in said shunt, said contact adapted to form a first branch between the zero end of the first resistor and said contact, means adapted for varying the length of the second resistor to form a branch having a resistance value directly proportional to a quantity to be-measured, a standard circuit having a potential proportional to the potential of said main circuit, and means actuated by the unbalancing of said shunt and standard circuits adapted for moving the contact upon the first resistor to a position to restore a balance bebranch.

9. A measuring system comprising a main elec- 35 trical circuit including-a source of potential, a

first resistor in said circuit, a contact movable,

upon the first resistor, a shunt circuit including said contact, a second resistor included in said shunt,'said contact adapted to form a first branch 40 between the zero end of the first resistor and said contact, means adapted for varying .the

length of the second resistorto form a branch having a resistance value directly proportional to a quantity to be measured, a standard circuit 45 having a potential proportional to the potential of said main'circuit, a galvanometer actuated by the unbalancing of said shunt and standard circuits, and means controlled by the galvanometer adapted for moving the contact upon the go first resistorto a position to restore a balance between said shunt and standard circuits, whereby the position oi. said-contact from. the .aero end'ot the first resistor indicates a resistance value of the first branch which is proportional to the square root of the resistance value of said second branch.

imum values of said second resistor.

11. A measuring system comprising a main electrical circuitincluding a source of potential,

a first resistor in said circuit, a contact mov- I able upon the first resistor, a shunt circuit including said ccTntact, a second resistor included in said shunt, means for varying the resistance of the second resistor to a value directly proportional to a quantity to be measured, means controlled by the current flowing through said shunt and opposed by a bias of such value as to balance said means when said current has a value equal to the potential oi-the main circuit divided by the first-resistor, and a reversible motor controlled by. the last mentioned means and adapted for moving said contactupon the first resistor to a position for maintaining-said current through the shunt. t

12. A measuring system comprising a main electrical circuit including a source of potential,

a first resistor in said circuitna contact movable upon the-first resistor, a shunt circuit including said contact, a second resistor included *in said shunt, said contactadapted to form a first branch between the zero end oi'the first resistor and said contact, means adapted for varying the length of the second resistor to form a branch having a resistance value directly proportional to a quanthe first resistor to a position to restore a balance between said shunt and standard circuits,

and the position. of said contact from the zero end of the first resistor indicates a resistance value of the first-branch which is proportional to the 'square root of the resistance value of said a second branch.

13. A measuring'system comprising -a main electrical circuit including a sourceot potential,

a first resistor; in said circuit,-oa first' contact movably mounted upon thefirst resistor, a shunt circuit, a gaivanometer in said shunt 'andhaving a set reading corresponding to acurrent equal to" said: potential divided by the resistance oi the first resistor, a second resistor in said'shunt, a

' second contact adapted ifor varyinitheiresistance of the second resistor to'a :value tional to a quantity'rto be-measur" connected between said contacts anaviqsiiideagem said shunt, a reversible motor, 12a motor including the motor and a source-oi potential, means actuated by the galvanometer adapted for controlling the motor circuit;;for directing the first resistor will indicate a-value of the first resistance which is proportional to the square root oi the value of the portion of the second resistance included in' the shunt circuit.

14. A meter comprising a shaft,a stationary disk positioned on the shaft, an arm mounted for rotation about the shaft and positioned adjacent to the disk, a main electrical circuit including a source of potential, a first resistor mounted upon the periphery of the disk and included in said circuit, a contact plate mounted upon the arm and in sliding contact with said resistor, a

. 'shunt circuit including said plate, a secondresistor included in said shunt, contact means ina cluded in said shunt and-adapted for varying the resistance oi the second resistor, a reversible motor adapted for moving the'arm relatively to the first resistor, and means controlled by the variation of the current in said .shunt'trom a fixedvalue equal to said potential divided by the resistance oi the first resistor and adapted for roe tating the'motor ina direction for moving the arm and adjusting the contact plate upon the first. resistor for restoring the current through said shunt circuit to said fixed Valuer aaoacoo resistor.

15. A meter comprlsinga shaft, a stationary disk positioned on the shaft, an arm mounted for rotation about the shaft and positioned adjacent to the disk, a main electrical circuit including a source of potential a first resistor mounted upon the periphery of the disk'andincluded in said circuit, a contact plate mounted upon the arm and in sliding contact'with said resistor, a

shunt circuit. including said plate, a second resistor included in said shunt, contact means ineluded in said shunt and adapted for varying the resistance of the second resistor, a reversible motor adapted for moving the arm relatively to the first resistor, means controlled by the variation of the current in said shunt from a fixed value equal to said potential divided by the resistance or the first resistor, and adapted for rotating the motor in a direction for moving the arm and adjusting the contact plateupon the first resistor for restoring the current through said shunt'circult to said fixed value, a fixed support positioned adjacent to the disk, and adjusting means associated with the-disk and said support adapted for. ad-

;iusting the angular positionoi the disk.

16. A meter comprising a shaft, a disk positioned on the shaft, an arm mounted for rotation about the shaft and positioned adjacent to the disk; a main electrical circuit including a source of potentiaLa first resistor mounted upon the periphery of the ,diskfand included'in said circuit, a' contact plate mounted uponthe arm and in sliding contact with said resistor, a shunt circuit including said plate, a second resistor included in said shuntr contact means included in said shunt and adapted ior varyingthe resistan'ceof the second resistor, a reversible motor adapted formdving the arm relatively to the first re- .sistor, meanscontrolled by the variation of the rrent-in said'shunt from a fixed value equal,

saidspgtential divided by the resistance of the ,esistorjand adapted for rotating the motor tolsaid fixed value, a" dial having, a scalethereon Landgraduated proportionally tothe length oi-the first resistor, means mounting the dial in a fixed position adjacent to the arm, 'and'a pointer mounted for movement with-said arm and lo cated'adjacentto'the said scale.

- 17. A meter comprising a main electrical circuit including a source oi potential, 'a'ofirstresistor insaid circuitga, shunt circuit, a second rethe shunt and opposed, bya bias oi such value as to balance said galvanometer when said current has a value equal to the potential of the --main circuit divided by the first resistor and a ;reversible motor controlled by the galvanometer and adapted for moving said contact upon the first resistorto a position for maintaining said current through the shunt to said value of the potential of the main circuit divided by the first 18. A meter comprising a' main electrical circuit including a source of potential, a first resistor in said circuit, a shunt circuit, a second resistor in said shunt, means adapted for varying the resistance of the second resistor'to a value directly proportional to the square of a quantity.

direction for moving the -arm"and adjusting the contact "plate uptn the, first resistor for re.-

. sto e current. hro h id h t rotation of the motor, and meansiactuatedbythe :1; th circuit motor and operatively associated with said first contact for. adjusting the latterupon the first-rej sistor to a position in which the current in said shunt is of the same value as saidset reading.- and the position 01' the first contact upon the on thefirst resistor for varying the current in said shunt to a value proportional to said standard current, and indicating means actuated by said contact adapted for indicating a value of the first resistance proportional to the square root of the value of the portion or said second resistance which is included in the shut circuit.

19.7A meter comprising a shaft, a stationary disk positioned upon the shaft, a main electrical circuit'inciuding a source of potential, a first resistor included in said circuit. means mounting said. resistor .upon a segmental portion of the periphery of the disk, an arm loosely mounted for rotation about said shaft. a contact plate mounted upon the arm and movable in contact with said resisto a'shunt circuit including said contact, a second resistor included in said shunt, means adapted for varying the resistance value of the second resistor, a third circuit having a standard current, a galvanometer biased by said- -standard current and balanced by the current in said shunt, a reversible motor adapted for rotating said arm, and means actuated by the gal-.

vanometer adapted torcontrolling the direction of rotation of the motor for adjusting said contactcarriedbythearmtoapositionuponthe first'resistor in which the current through said shunt will balance said standard current and the radial position of the arm carrying said contact will indicate a resistance value of the first resistor which is proportional to the square'root o! the resistance value of the second resistor.

20. A meter comprising a main electrical cir-. cuit, a first resistor in said circuit, a contact movable upon the first resistor, a shunt circuit in-. cluding said contact, a second resistor included in said shunt, said contact adapted tororma first branch between the zero 'end of the first resistor and said contact, means adapted ior varying the length or the second resistor to form a second branch having a resistance value directly proporti'onal'to a quantity, a galvanometer included in said shunt' and actuated in one direction by the current in said shunt against a bias of such value as to balance the galvanometer when said current has avalue equal to the potential of the main circuit divided by the first I resistor, and a reversible motor controlled by the galvanometer and adapted for adjusting said contact upon the first resistor for maintaining the galvanometerin balance and the resistance of the portion of thefirst resistor included in I the first branch proportional to-the square root of the resistance of the portion 01- the second re' sistor includedin the second branch.

21.Ameteras claimedincla'inrmhavinga scale graduated proportionally. to the length oi Q the first resistor, and a pointer located adjacent to the scale and movable in unison with the contact upon the first resistor.

* EMORY FRANK STOVEB. 

